Instantiating function from type?

[nsajko]

@stevengj

F() doesn’t work, but I feel like it should

Related thread:

Constructors for `<:Function` types when possible, like in C++

I was thinking about how C++20 added support for default constructors for stateless (with no captures) lambdas, meaning that nowadays all function object families may be default-constructible in C++. Then I realized that in Julia I can’t even do typeof(sqrt)(), or something like this: func(::F) where {F <: Function} = F()(5.0) func(sqrt) # Or this func(::Type{F}) where {F <: Function} = F()(5.0) func(typeof(sqrt)) Seems like passing “pure” functions as types, instead of as objects would make…